Speaking tube



April 17, l1934. G. R. MARTIN SPEAKING TUBE Filed Jan. 25. 1933 WZZ/z ess ein Patented Apr. 17, 1934 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to speaking tubes and has more particularly to do with the mouth piece or auditory terminal portion thereof, the object to produce a combined transmitting and receiving terminal by the use of which the speaker may clearly hear not only the sound of his own voice but that of the person at the opposite terminal of the tube without necessitating the movement of the head to bring the mouth and ear alternately in range of the terminal, as is necessary where a single opening is provided for both sound transmitting and receiving, and to attain certain other advantages which will hereinafter more fully appear.

The invention consists broadly in the provision of the combined transmitting and receiving terminal in a speaking tube or system of tubes, and in the separate structural parts and combinations and arrangements of parts as hereinafter described and pointed out with particularity in the appended claim.

In the accompanying drawing illustrating a practical adaptation of the invention:

Fig. 1 is a front elevation of a combined transmitting and receiving terminal element;

Fig. 2 is a View at right angles to that shown in Fig. 1; and f Fig. 3 is a view partly in section and partl in elevation, and illustrates the relation of the parts from a top plan position.

'Ihe present invention is applicable to either a portable or a built-in speaking tube or system of tubes. That is to say, the dual terminal element may be incorporated with a speaking tube which is installed upon or built into the different parts of a building, or it may be used with equal facility in connection with a exible or other portable speaking tube.

As shown in the drawing, the numeral 5 designates a, tubular member for attachment to the tube or conduit proper (not shown) which, as above stated, may be of any ordinary kind and installation. Sleeved on one end portion of the member 5 is the tubular stem portion 6 of a T- member 7, in the opposite end portions of which are inserted the leg portions 8 and 9, respectively, of tubular elbows 10 and 11. Preferably, the T- member 7 is fitted rotatably with respect to the tubular member 5, as are also the elbow members 10 and l1 with respect to said T-member, and the said connections between the several members are also preferably longitudinally adjustable.

Fitted in the elbow members 10 and 11 are the shank portions 12 and 13, respectively, of terminal members 14 and 15 which, as far as the present invention is concerned, may be identical. As shown, the shank portions 12 and 13 of said members 14 and 15 are preferably tapered and tted internally in the elbow members 10 and 11, the outer end portions of said terminal members 14 and 15 being flared or bell shaped, as at 16, the marginal portions thereof being rebent cylindrically, as at-17, and beaded annularly at their extreme edge portions, as at 18.

In using a speaking tube terminally equipped in accordance with the present invention, the speaker places his mouth in close proximity to one of the terminal members 14 or 15, and speaks directly therethrough into the tube as with the ordinary mouthpiece, and any sound transmitted through the tube, whether it be that of his own voice or coming from another person at the other end of the tube is clearly heard by him through the companion terminal member 14 or 15, as the case may be, because the speaker may readily adjust the head to locate his ear within hearing range of said last named terminal member Without moving his mouth from effective sound transmitting range of the first mentioned terminal member, which is a material advantage over the ordinary single terminal opening in the use of which it is necessary for the speaker to keep moving his head to alternately bring his mouth and ear into effective range of said single terminal opening in carrying on a conversation through the tube.

Obviously, the structure may be modified in the many adaptations of the invention within the scope of the appended claim. The invention, therefore, is not limited to the exact construction and arrangement shown in the accompanying drawing.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

A terminal construction for speaking tubes comprising a tubular T-member, elbow members fitted to the opposite end of said T-member with rotative and longitudinal adjustment, and like terminal elements fitted to the outer ends of said elbow members for sound reception and delivery.

GEORGE R. MARTIN. 

